Fix lack of standard cut-paste behavior in text box

[zedsaeed]

At the moment Scribbeo does not seem to adhere to the standard cut-paste features that Apple has placed in iOS. For example, after copying some text in an email, if the user goes to Scribbeo and clicks and holds down inside teh tet box, the Paste pop-up does not appear. (This seems in violation of standard behavior on iOS apps.) We should make sure we fully conform. we should allow users to Cut text away from the text box as well as be able to Paste inside it from another app.